Coherent sources and wave optics
Compact sources of coherent radiation — such as pulsars, FRBs, and gravitational waves — propagate and scatter in the wave regime of optics. The resulting chromatic interference effects contain un-tapped information which may shed light on a variety of regimes of physical interest: e.g., the interstellar medium and dark matter. I work on systematically characterizing wave effects in different lensing scenarios. See this review on wave optics in astrophysics.